Liquid transmission systems



July 18, 1951 G. B. RICHARDS 2,992,757

LIQUID TRANSMISSION SYSTEMS ATTORNEYS July 18, 1961 G. B. RICHARDS LIQUID TRANSMISSION SYSTEMS 6 Sheets-Sheet 2 Original Filed Dec. 16, 1955 INVENTOR GEORGE B. RICHARDS ATTORNEYS July 18, 1961 G. B. RICHARDS LIQUID TRANSMISSION SYSTEMS Original Filed Dec. 16, 1955 6 Sheets-Sheet 3 FIG.||

INVENTO'R GEORGE B. RICHARDS BY JMA, W

ATTORNEYS July 18, 1961 G. B. RICHARDS 2,992,757

LIQUID TRANSMISSION SYSTEMS Original Filed Deo. 16, 1955 6 Sheets-Sheet 4 INVENTOR GEORGE B. RICHARDS BY ATTORNEYS July 18, 1961 G. B. RICHARDS 2,992,757

LIQUID TRANSMISSION SYSTEMS Original Filed Deo. 16, 1955 6 Sheets-Sheet 5 INVENTOR Y GEORGE B. RICHARDS B ATTORNEYS 6 Sheets-Sheet 6 G. B. RICHARDS LIQUID TRANSMISSION SYSTEMS July 18, 1961 Original Filed DeG. 16, 1955 INVENTOR.

GEORGE B. RICHARDS ATTORNEYS Patented July 18, 1961 United States Patent Gflice 2,992,757 A LIQUID TRANSMISSION SYSTEMS GeorgerBL Richard`s,fDeerleld,` lll., assignor' to Liquid Controls Corporation, Chicago, lll., a corporation of Illinois"v Continuation ol? application Ser. No. 553,506, Dec. 16,` 1955.` Thisfapplcation Feb. 24, 1959, Ser. No. 795,153 14^Claims. (CL2Z2-61) invention relates to liquid transmission systems and has to do more particularly with means for stopping the ilow of-the principal fluid through the system whenever an undesired, second uid, such as airv or other gas, or another and immiscibIe-liquid, enters the system along with the principal liquid.

Flow in a liquid transmission system is produced by establishing a dilferential pressure between the inlet and the outlet of the system. This may be accomplished'by line. conducting a petroleum product such as gasoline",- it

isdesirable to` prevent the passage of air or other gases, or water. v

In discharging liquids from storage tanks or the lrke it is customary to providei'in'the discharge line means; such asa meter, for measuring the amount of liquid discharge. In discharging a tank, airimay enter the discharge connection, `as for example when-the `tank is comY- pletely discharged andL before theoperator halts 'the' further discharge, or where the discharge is transfer'red` from one tank to another or onecompartment of a tank to another compartment, with the result that themeter' willVcontinue-to `operate and to `indicate thelilowofuid,

even ater the liquid has ceased topasseth'erethroughand air or lother gases pass through themeter',' thereby` ind correctly indicating a llow of liquid.

Another instance l where it is fdesirablelto prevent-the flow off air ,orf other gasthrough aliquid system is Where* liquid tanks -are` dischargedV by gravity and to aidthe action of gravity, gas under pressure is introduced into the'tank.

In. such case, unless theoperator constantly observesfthe discharging of the tank and stops the flowof fluids therefrom as soon asthe liquid is `fullydischarged, air or other gas will-how fromvthe tank and theepressure will-"be` reduced or entirely lost. It is important to prevent such lossof pressure where'severalinterconneoted compartments of a singleltankr arebeing discharged successively bytherapplication of gaseous pressure thereto.

The presence of air or other-:gas in a liquidsystem also is undesirable'wherea pumpis connected inlthe system on the downstream side of a tank.` It is importantin such`casetoprevent t air from enteringthe pump in order to prevent loss ofpriming of the pump. Other instances@ where the pressure of`air or .other gases is undesirablef and should be -prevented are where liquids are caused `to ow through long lines, and where liquid pumps:` are' operated unattended for longperiodsof time.`

In addition to theforegoing, `it is sometimes desired' to prevent the passage through a liquid transmission lineof a secondary undesired liquid. For example, in Withdrawing the heavier of two immiscible liquids from a tank in which both liquids are"present, it is desirable that only the heavier liquid pass `through the discharge line.'

Means, such as air eliminators, havebeenprovided heretofore for removing air or-other gas" from liquidsystems. However, it has beenfound that such means are not elective in all cases for preventing the passage of aifr` or other gas through the system.

"Customarily, means are provided for-creating artificially the necessary pressure differential over the air eliminator to insure that all air or other gas is discharged thereby. For this purpose a tloatlactuated check valve is employed in a gravity and/or'pump operation and a spring-loaded check valve is used where a pump alone is employed. `Float-actuated valves, which are usually of the butterfly type, are not satisfactory as they are not liuid tight, create turbulence, are unreliable in operation, require operating linkages which are space-consurning and become fouled by congealed oils and gums, frequently close even though no air or other gas is present, frequentlylock closed and fail to open, cause substantial pressure loss even when open, andv require a large con tainer for fthe oat with attendant disadvantages. Spring loaded check valves cause -a high back pressure at all times, induce wire drawing and vaporization at low ows, cannot be-used with gravity ow systems, cannot relieve heatfexpansion pressure in the fluid and present diculty to the pump in picking up the prime where there is a high, xed discharge head.

. An objectof the present invention is to provide new and improved apparatus for preventing the tlowjof a secondary and undesired uid-through a line adapted" to transmit a primary liquid.

Another object is `to providernew and `improved apparatus for halting the owthrough a liquid transmission line having means therein for dischargingan undesired secondary fluid whenever the iluid discharging meansis7 incapable of discharging all of the undesired lluid from the line p Another objectis the provisionbof new and improved apparatusfor measuring liquid ow.

Another object is to provide new and improved apparatus for measuring liquid ow which `is not subject' to inaccuracies resulting from the passage of air or other secondary lliiids intoA the apparatus.

Another object-is to provide liquid flow measuring'apparatus in which is` embodied means for automatically stopping the" flow of udthroughthe apparatus when` ever a secondaryfluid passes into the apparatus and-before `it passes throughthe yrneter,` whereby no inaccuracies in measuring can result from the passage of -air through the meter.

Anotherobject is to provide liquid ow measuring ap` paratus is simple and compact and is -wellr adaptedfor` installation in a large `varietyof dierent types of liquid conduits."

Other "objects are toprovide apparatus torrdischargingY air "or other iluidsffrom a liquid line and for halting the flow of huid through a liquid line` when the gas discharging means is incapable of discharging all ofthe air or other fluid from .the line, which apparatus-effectively closes `the line'when, and only when, air or another second'fluidentersthe line in excess of the capacity of the lluidfdischarging means; which is effective and reliableV in lines *of-` various diameters includingv large `diameter lines; which is vnot subject to malfunctioning because of foulingor other causes; which is readily restored to'its initalconditionrtoallow liqiud to ow through the line; whichl is so-constructedas notto cause "excessive pressureloss in thelline; which `is smalldand `compact;which FIG. 3 is a side elevational view of apparatus includ-r ing a strainer-air eliminator-meter-valve assembly embodying the present invention;

FIG. 4 is an end elevational view of the assembly of FIG. 3;

FIG. 5 is a fragmentary horizontal sectional view taken along line 5-5 of FIG. 3;

FIG. 6 is a fragmentary, somewhat diagrammatic, Vertical sectional view showing the interior of the meter forming a portion of the apparatus;

FIG. 7 is an enlarged vertical sectional view through the air eliminator head;

FIG. 8 is a view similar to FIG. 7, only taken along a vertical plane in right angles to the plane of FIG. 7;

FIG. 9 is a view of a section taken along line 9-9 of FIG. 7;

FIG. 10 is an end elevational view of the air eliminator of FIG. 7;

FIG. 1l is an enlarged fragmentary sectional view taken along line 1l-11 of FIG. 7;

FIG. 12 is a side elevational view of the cut-oi Valve;

FIG. 13 is a top plan view of the cut-off valve;

FIG. 14 is a vertical section taken on line 14-14 of FIG. 13;

FIG. 15 is a fragmentary sectional view taken along line 15-15 of FIG. 14;

FIG. 16 is a fragmentary side elevational view, with certain of the parts broken -away and in section, showing the automatic stop mechanism;

FIG. 17 is a diagrammatic view of a system wherein positive pump pressure is employed to force the liquid through the line;

FIG. 18 is a view similar to FIG. 17, but showing a system wherein the force of gravity alone is employed to cause the ow of liquid; land FIG. 19 is a view similar to FIG. 16 but showing a system wherein pump suction is employed for producing the iow.

In accordance with the present invention I provide a liquid flow system including a cut-off valve for stopping the flow of fluid through the system and control mechanism actuated by the presence of an undesired, secondary fluid therein for causing the cut-off valve to close. 'Ihe undesired secondary uid in many applications of my invention will consist of air, or a mixture of air and vapors of the liquid being transmitted as are present, for example, in a line employed in discharging a gasoline tank. However, the undesired fluid may instead consist of a liquid which is immiscible with the primary liquid, or both such a liquid and a gas. Therefore, while I have described the invention in connection with its use in discharging a gas, it will be understood that the invention is not thus limited. In the preferred embodiment of my invention the cut-oif valve is normally urged toward closed position and is held open by the control mechanism which includes a latch' and tripping means therefor. An air eliminator is connected in the line and serves both to discharge air or other fluid `from the line and to actuate the tripping means.

For the purpose of illustrating my invention I haveV shown it in connection with application to a system wherein the ow is effected by pressurizing the tank to be discharged, such as ydisclosed and claimed in the copending application of Henry Robert Billeter and George B. Richards, Serial No. 553,592, iiled December 16, 1955, now Patent No. 2,894,659. It will be understood however, that my invention is not limited to such application but is applicable `also to a system wherein a pump is employed to force the liquid through the line, or wherein gravity is employed, or a pump suction is used to draw the liquid through the line.

Referring now particularly to FIG. 1, there is shown for purposes of illustration a tank truck including a tractor unit 21 and a semi-trailer 22 having a closed (unvented) tank 24. Carried by the tractor 21 and forming a portion thereof is the usual internal combustion engine 201 anda system for pressurizing the tank 24. Such system includes an exhaust line 25 leading from the internal combustion engine 20, a pressure regulator 27, a fire stop or ilame arrester 28, an intercooler or heat exchanger 29 and a flexible pipe hose 30 connecting with a gas inlet manifold 31 which communicates to inlets 32 with each of the several compartments 33 of the tank 24. Such an arrangement for pressurizing a tank is disclosed more in detail in the aforementioned copending application of Henry Robert Billeter and George B. Richards.

Leading from the several compartments 33 are discharge pipes 35 all of which are conected with a discharge manifold 36 including valves 48 controlling iiow through the several pipes 35 respectively. A single outlet pipe 37 connected to the discharge manifold leads to a strainer 38 with which is associated an air eliminator 39. The strainer casing is connected to a meter 40 which in turn is-connected to a cut-dif valve 41, actuated from the air eliminator by a valve control mechanism 249 (see FIG. 16).

The internal combustion engine 20, exhaust line 25,

muier 26, pressure regulator 27, fire stop 28, intercooler- 29, pipe 30, and the connected portion of the coupling 4 3, are carried by the tractor unit. The remainder of the coupling 43, swing check valve 44, manifold 311, discharge pipes 35, manifold 36, outlet pipe 37, strainer 38, air eliminator 39, meter 40, cut-off valve 41, valve control mechanism 249, and hose 42 are carried by the semitrailer unit.

Connected to the cut-off valve 41 is a discharge line 42 which preferably takes the form of a ilexible hose and is adapted to be carried on the semi-trailer forl conA nection to a lead-in pipe 50 of a stationary tank 51 into which the liquid from the tank truck is adapted to be discharged. For this purpose a separable coupling 49 is provided for connecting the pipe or hose 42 to the inlet pipe 50.

The semi-trailer unit 22 is provided with the usual compartment or cab-inet 52 in which the discharge manifold 36, Ithe strainer 38, air eliminator 39, meter 40, shut-off valve 41, and discharge hose 42 are housed, the compartment being provided with the usual doors 53 by which access may be obtained to the interior of the compartment. The strainer 38, air eliminator 39, meter 40 (which includes a counter 40a) and cut-off valve 41, as well as the actuating mechanism (hereinafter described) for the cut-oi valve preferably all are assembled to form a unitary structure as shown.

The strainer 38 may be of any suitable conventional construction and is disposed in a casing having its inlet adapted to be connected to pipe 37 forming a portion of the line in which the apparatus is connected and Disposed `above and t connected to: the strainerxcasingk is an air eliminator 39 the purpose of .whichtisrthefreetmovalifiiom the line of any-air or other gas which may enter4 the-:line so that no` air or=- other .gasz passes through* the meter-whereby the meter accurately'meters the liquid passing through the line;

The. air eliminator preferably is formed as..disclosed in. thecopending application ofHenryIRDbeIt Billeter `and George BQ'Richards, tiled June l, 1955,\Serial No. 512,- 551 nowabandonedand replaced by continuation application Serial No. 775,077 and divisional application Serial No.\775,045, bothile'd November 19,- 1958.

The air eliminator 39 includes a casing 130 `defining a float chamber 131 (see FIGS; 7 and 8) whichis` in communicationat its lower endwith the interior of the strainer casing through openingsA 1133 formed in a plate 134 secured in the casing` for apurpose which will appear f hereinafter. The air eliminator casing 130 is secured to the casing 120 in sealing relation therewith.

The casing 130 is provided at its upper portion ,with 1 openings 139a and ,139b` at opposite portionsxlthereo; which openings are closed by end plates 14th:` and 140b respectively secured to the casing and provided with open. ings 142a and 14212 4into which are threaded pipes 143 and 144..

The pipe .143 leads to thecylinder 256 of the valve control mechanism 249 and the pipe 144 leads intoone of the tank compartments 33 and-is provided with` acheck valve 144a,A all fora purpose hereinafter` explained-.

Secured between the casing 130and each of the end plates respectively are orice plates 145a and 14512 pro-i` vided with elongate orices 146:1 and 14617 respectively. Theend `plates aand 140b are recessed and provide i withthe respective oriiice plates 14511 and b, chambers `147a and 147b which communicate `with the float.V chamber through the orifices 146a and 146b, exceptwhenthe latter are closed by thevalves hereinafter described.

Suitablysecured in place against the inner faces of the oriiceplates 145a and 145b are' cover gaskets 160a and i), formed Withorices 161a and 161b corresponding in shape to the orifices 146a and 146b. Thecover gaskets `are formed from a suitable resilient material, such as plastic, which is suiciently resilient to provide an effective seal between the respective members and which is resistant` to the liquid with which the air eliminator is` adapted to be used. Ring gaskets 162a and 162k, pref-i erably ofsimilar material, are provided between the `casing .130iand end plates 140g and 140b respectively.`

The-chambers 147a and l47bareconnected'by'a pas.- sage- 14Sitormed in the upper portion of the casing 130. The Voritice plate 145b is provided with a corresponding opening 1\49*(see FIG; l1) registering with the passage 148, `and the gasket 160b is provided with -a similar opening (not shown), whereby to .permit communication between the chambers 147:1 and 147 b.

A flap or reed valve 163 is secured tothe-orifice plate 14511 which permits air to flow through the passage 148 from the. chamber 147a to the. chamber 147b` but prevents reverseow of air,` fora purpose which will hereinafter appear.

The orices `146a and 146b are adapted toghe closed by valveslla and 151b which are similar in construction and accordingly only onel of the valves and the associated portionszof the `air eliminator will be described in detail. When the valves are in open position, the float chamber 131 communicates with the pipe 143 through the left hand orifice 146a and with the pipe 144 through the right hand orifice 146b.

The valve 151e takes the form of an `elongated flat` stripof iexible, resilient material,= preferably metal, which isinert to the liquid with which'the air eliminatorf` isr adapted ...to be used; While anyA spring material having i suitable flexibility, resiliency `and inertnessmiayfbe ,used,

I have found :that'fa springsteekalloy soldunderf the namev =Elgi1yi yprovides f excellent; aresultszf- Thetvalve -151a is ofi` sucienhwidth to extend` across-.- and completely close'then-on'tce` Y146a when the :valvewis in closed position and is of sucient `length to permitity to fben mounted and iactuated as hereinafter described;

The valvestriporelement `151a isrigidly secured suiti ablytothe casing atiazpoint below `the orice 146:1 and in such :position thatthe adjacentf'portion of the strip lies :1

, against the inner face of the cover `gasket 160:1 at all times;

The `other end ofsthe-:valve element or strip151ais attached as. by a'rivet180fto a tubular stem l170 forming 1: a por-tion of a float 172. The stem extends .throughl andis `sealinglysecured inthe ball portion .173 ofthe float Vandfprojects :thereromat each end. The 'stemf 170 is hollow and receivesA an'V upstanding guide` post-174e Which`is rigidly secured in-andA upstanding fromlthe plate.;A 134. The `stem 170 thus serves; to guide the oat 172 for',` movement in a ,verticaldirection within the float chamber. J 131.

The-.other valveelement: 151b. is `.secured/to the casing andtothe stem.170in asimilar manner but reversedlpof sition .so that. itY isv positioned againstthe inner faceof. thegasket 160b and thetwo valve elements 151a and 151b ilmutually abut` at their portions adjacentithe endswhich are `secured to the `stern 17 0. t

EachV of the valve elements 1'51a and 151`b is so secured to and supported by the casing. 1.30 and the float 17=2 that inrall positions thereof throughoutits range of movement from its lower, open position (as shown in broken lines in' FIG. 7) to its upper, closed position (as shown in full lines inFIG. 7 it has a free portionextending betweenl f the portion which bears against the-face of the orifice plate'.` and the portionwhich `bears against the other valve element, which free portion is bent back upon itselfV and assumes a curved shape. The free `portion retainsthe` same curvature in all positions of the oat. This isU eiected byattaching the valve element, only at4 its ends, to the casing and float respect-ivelyV and providi-ngffor` movement of the float in a direction parallel to the face of the orice plates.

The two valve elements 151a and 151b are connected"` to the casing 130 and to the stem l170at diametrically'op posite points whereby the two valves 151:1 and l151bare` disposed in opposition. Accordingly, they exert on'the stem-170 and accordingly on the oat 172 equal and op4 posite forces so that the float normally islfreelysupported" bythe valve elements 151a and 151b in the oat cham-h ber and does* not bear against the guide stem .174; The.

u guide stem` 174 however is provided so. as to insure true vertical movement of the float 17-2 in a direction parallel` to the faces of the orifice plates '145:1 and 14l5b.

Since the assembly'consisting of the valve elements` 1,5121 and 151b, and the iloat 172 is freely supported, .the forces exerted by therespective valve elements 1'S1a and' 1511)` against their respective orifice plates 1-45a and145b.v (that` is, againstthe gaskets 160a .and 1601;) are equal,` Iand the valves, therefore, yare completely balanced against:H each other.

Moreover, the arrangement` is such that` each .ofthe valves 151a and 151b is under stress-throughout itsentifre` range of movement, which stress .causes the valve .toben urged against its orifice plate throughout` at least a portion ofthe valve during its entire range of movement.` As will `be seen from the drawings, when the float is inits. f lower position the valves 151:1 and 151b bear against the' faces of. their respective orice4 plates 14.5afand'145b throughout `only the lower portions of the valves and at an area on each of the orifice plates below the oriices` 146:11'` and 146b. However, as the oat `172 rises-to its upper position, asl established by the `abutmentoffthe lower-inw turnedendof the stem 170aga-inst` a stop -175'formed in n the upper end of the stem 174, the valvesx1541`a.` andf15'1b i" bear against their respective orifice platesat portions em tirelynsurrounding `the orifices in order to lprovide com@ plete closures for the two orifices 146a and 146b. Thus it will be seen that valve elements 151a and 151b are urged into their positions closing and sealing the orifices 146a and 146b by the resilience of the valve elements 151a and 151bY themselves.

Assuming that the gas has been removed and liquid stands in the air eliminator 39 at -a level sufficient to raise the oat to its uppermost position, the valves xi1a and 151b are in closed positions. Thus the valves lie against their respective orifice plates 14511 and 145b and extend entirely over and sea-lingly close the respective orifices 146a and 146b so that no liquid can escape from the head.

It wil-l be noted that the valves 15111 and 151b lie flat against their respective orifice plates throughout a substantial zone thereof and particularly a zone on both sides of 'and above and =below the orifices 146a and 146b so that the latter are fully closed. As noted above, the spring pressure of the valves 151aand 151b provided by reason of their bowed or curved form insures that the closing portions thereof are maintained against their respective orifice plates regardless of the presence of any air or liquid pressure within the float chamber 131.Y

When gas enters the float chamber 131 from the strainer casing, such air displaces the liquid in the iioat chamber 131 and causes the level to fall. When this occurs, the float 172, which is buoyantly supported by the liquid, also-falls and carries with it the stem 170 to which the valves 151a and 151b are attached. The downward movement of the stem 170 causes the ends of the valves 151a and 151b attached thereto to move downwardly in a direction parallel to the faces of the orifice plates with the result that the portions of the valves 151a and 151b which previously lay against the orifice plates are stripped or peeled away from the orifice plates 145a and 145b progressively downwardly, and as the downward movement of the float continues the orifices 146a and 146b are progressively uncovered in a direction from the upper portions thereof toward the lower portions.

As soon as the orifices 146a and 146b have been uncovered by the above-described opening movement of the valves 151a and 151b, the gas trapped in the float chamber 131 above the level of the liquid in the system and which normally is under some pressure is caused to flow out of the float chamber through the orifices 146a and 146b and the pipes 143a and 144 for a purpose which will hereinafter appear.

When the gas has been discharged to such an extent that the liquid level rises sufficiently to support and lift the iioat 172, the latter is elevated and causes the valves 151a and 151b to be moved in a reverse direction to that described above in connection with the opening of the valve. That is to say, that as the iioat 72 moves upwardly the valves are caused to progressively move against their respective orifice plates to an increasing degree and to progressively close their respective orifices until the orifices yare completely closed and the valves extend in contact with their respective orifice plates both above and below the orifices. When the valves are closed, no further gas can escape from the float chamber 131.

kThe meter 40 may be any suitable form of meter for measuring the flow of liquids therethrough, but I prefer to employ a meter such as shown and described in my copending application Serial No. 522,930, filed July 19, 1955, now Patent No. 2,835,229, dated May 20, 1958, to which reference may be made for a more detailed disclosure of the meter.

Briefly, the meter 40 includes the hollow casing 121 having an inlet port 180 connected to the outlet of the strainer casing 120, and an outlet port 181 leading to the casing 182 of the shut-off valve 41. The casing 121 has a pair of semi-cylindrical, rotor-sealing wall portions 183 and 184 defining inlet and outlet cavities or chambers 185 and 186 which are in free communication. The casing 121 also'has a blocking wall portion 187 extending between theinlet andoutlet ports 180 and 181 on the opposite side of the casing from the rotor-sealing Wall por-u tions 183 and 184.

A pair of displacement rotors 190 and 191 which `also are referred to as inlet and outlet rotors, respectively, are rotatably mounted in the casing 121 in position to pass in sealing relation with the wall portions 183 and 184 for approximately 180 of their rotation respectively. Rotatably mounted in the casing 121 is a blocking rotor 192 having oppositely disposed peripheral, sealing wall portions 193a and 193b of convex circular form positioned to pass alternately in sealing relation with the blocking wall portion 187. The blocking rotor 192 is provided intermediate the peripheral portions 193e and 19317 with deep recesses 194a and 194k adapted to permit the displacement rotors 190 and 191 to pass successively,

therethrough during the rotation of the rotors las hereinafter explained. The blocking wall portionk 187 is of such dimension relatively to the peripheral portions `re,- spectively of the blocking rotor that a complete seal is provided between the blocking wall portion 187 and the blocking rotor 192 at all times during the rotation of the blocking rotor. That is to say, either one or the other of the peripheral or blocking surfaces 193a 'and 19317 of the blocking rotor 192 is always in sealing engagement with the blocking wall portion 187.

The peripheral portions 193e and 193b which also serve as sealing portions of the blocking rotor 192 are4 disposed to pass in sealing relation with the displacement rotors 190 and 191 when the latter are in sealing relation with their respective sealing wall portions 183 and 184 so that the blocking rotor 192 and the respective one of thel displacement rotors provide a three point seal with each other and with the casing, namely, a seal between the displacement rotor and its corresponding sealing wall portion, between the displacement rotor and the corresponding portion of the blocking rotor, and between the other peripheral or sealing portion of the blocking rotor and the blocking wall portion of the casing.

The two displacement rotors 190 and 191 are drivingly connected to the blocking rotor 192 by gears (not shown) in such angular relation that the rotors rotate simultaneously in a fixed phase relation whereby first one and then the other of the displacement rotors is in sealing relation with its corresponding sealing wall portion of the casing and simultaneously in sealing relation with the blocking rotor, while the other displacement rotor is in spaced relation with the casing and with the blocking rotor. It will be noted that the recesses 194a and 19417 of the blocking rotor are of such depth and peripheral extent as to permit the respective displacement rotors to pass therethrough freely and without any sealing effect.

The blocking rotor 192 is connected to and drives a shaft 195 which is drivingly connected to a counter 40a mounted on the meter casing and which serves to count the revolutions of the blocking rotor and thus Aindicate the volume of liquid which passes through the meter. The counter 40a may be of any suitable construction and the details thereof form no part of the present in- Vention.

The operation of the meter is as explained more in detail in my copending application above referred to. Briefly, liquid flows into the meter casing through the inlet and out of the outlet 181. In passing through the casing the liquid causes the displacement rotors 190 and 191 to be rotated and, since they are connected to the blocking rotor, the llatter is rotated at an angular velocity and angular relationship relatively to the displacement rotors determined by the gearing. In the present illustrative embodiment of the meter the gearing is so selected and arranged that the blocking rotor is rotated at an angular velocity of one-half that of the displacement rotors.

During each cycle of operation the inlet rotor 190 first closes the cavity by engagement with the sealing wall surface 183 and with one of the sealing surfaces of the blocking rotor 192 and then sweeps around the .sealing -wall surface 183 `in sealing relation therewith. During this portion of thecycle the outlet rotor 191 'passes through one of Vthe cavities inthe blocking rotor 1in spaced relation `to the `blocking rotor and in spaced relation tothe sealing wall surface 184 so that this rotor is not in a sealing or` active phase. When the inlet rotor 190 reaches the end of the sealing wallsurface v183 and .just `as it breaks the seal with that surface and with Athe blocking rotor 192, the outlet rotor 191 engages the sealing wall surface 184 in sealing relation and also `the blocking rotor 192 in sealing relation with one of the sealing-surfaces thereof. Thus, as the Seal between the `inlet rotor 190 andthe casing and the blocking rotor is broken, the seal between the outlet rotor 191 and the casing and with the blockingrotor` is made.

It will be seen, therefore, that during `each complete `revolution of one of the displacement rotors a volume of liquid is displaced which is equal to twice the effective volume of one or the otherof the cavities and since each displacement bladefsweeps its cavity twice during a full cycle of the meter (that is, one revolution of theblocking rotor), it follows that a quantity of liquid is displaced Iduring each cycle of the meter equal to -four times the effective Volume of one of the cavities.

Referringnow particularly to FIGS. l2 to 15, there is illustrated the cut-oli valve 41, in whichviews the valve is shown in closed position contrary tothe showing in FIG. 16 in which the valve is shown in open position. The function of this valve is to shut olf the flow of `liquid through the meter `whenever `air enters the line in which the meter is connected in order to prevent `a false reading of the amount ofthe liquid passing through the meter, which would result if air were permitted to pass through the meter. The cut-off valve 41 `may be of any suitable construction but preferably `is a b-alanced valve embodying certain `principles of the valve disclosed and claimed in my copending application, Serial No. 390,874, filed March 9, 1954, now abandoned.

The cut-oli valve `41 includes a hollow casing 200 having an inlet 201 connected to the outlet .181 of the meter and an outlet `202 connected to the discharge hose `42. Thevalve housing A200 preferably is formed byan inlet section 203, a seat member 204 providingla valve seat and an outlet section `205 defining a chamber 211, the sections being suitably secured together as by bolts `206. The joints between the housing section are sealed as by rings `208 and207.

The valve seat member204 is provided `with a passage .210 therethrough which connects the inlet 201 with Vthe chamber 211 of the outlet section `210 from which leads the outlet 202. A cylindrical valve guide 212 is rigidly supported in the chamber 211, as by a hollow post 213 secured in the inlet section 203. A generally cup-shaped valve element 214 is supported on the valve guide 212 for Vertical sliding movement thereon between a position wherein the lower end of the valve element 214 closes against the seat member .204 and a position wherein vthe valve element 214is raised` above the valve seat member 204 and liquid is permitted to pass between the Valve seat section and ythe Valve element 214.

For the `purpose of providing an effective seal between the valve element 214 and the valve seat member 204, the latter is `provided with an upturned lip 204a surrounding the opening 210 and having an annular` groove 216 in which is recessed an 0 ring 217 providing a seal between the valve element 214 and the seat member 204 when the valve element 214 is yin its lower, closed position. The end edge or face of the valve `214 is inclined at an angle of 45 so that the end of the valve 214 rides over the O ring readily in moving into closed position.

The valve element 214 is sealingly supported on the valve guide 212 so that -when the valve element `214 `is in sealing relation against `the valve ,seat member `204 no liquid can -pass from the interior 'ofthe'valve Fele-l ment 214'below the valve-guide 212 and intorthe chaine ber 211. To this end a seal comprising Aan `0 ringr2-1-8 -seated `in a groove -in the valvenguide 212 `is provided.

The valve element, 21'4is normally urgedinto `elose'd position against the valve seat member `204 bya coiled spring 219 Vwhich is-seated at one end against the l"top `of `the casing section 205 and at the other end against a flange 220 formedon the outer portionof the valve element 214.

The valve element 214 is provided witha plurality -of openings 221a in its upper wall for the purposeof permitting liquid toV flow `freely through the `upper `wall wandthus prevent the 4establishment of a vacuum'between the valve `214 and the valve t guide 212 when the valve Aelement, 214 is lifted.

Slidably guided in the post 213 for vertical movement therein Yis a valve actuating rod `221 which extends through the bottomwall of the casing section 203-and is sealed therein -as by alseal 222. The rod 221 is adapted to be raised by a crank 223 pivotally supported by a pin 224 in a bracket 225 fixed to the casing of the valve 41.

The rod 221 at its upper portion projects from the valve guide 212 and abuts the upper wall 227a of the valve 214 whereby `upon upward movement of the rod `221 the vala/e214 is raised.

The valve guide is` provided with an upwardly opening recess having a-lower, enlarged portion 226 andlan upper reduced portion 227. Carried on the rod 221 is awasher 228 formed of flexible resilient material and dimensioned to have a sliding fit iinthe `upper portion 227 of therecess. Thewasher 228 is supported on the rod 221.as.by a split ring 229 and its upward movement relatively to the stemis limited by 'a flange 230 on the rod. The washer 228 is provided with a plurality of openings :231 providing passages'therethroughfor `a purpose which .will nowfappear.

In operation of the valve `-41,the valve is opened .by rocking the crank 223 in a clockwise direction which raises the valveelement' 214' away from the seat member 204,` and the valve element is held in open position until released (alll as hereinafter explained). At the same time the washer 228 is .moved into the reduced portion 227 of the recess. When the valve element is released, itfiS m'ovedtoward closed position by thespring 219. The washer 228 cooperates with the recess portions226 and 227 toprovide `an action in the nature of a dash pot faction, therebyto retard the closing movement of v.the valve element. In `this connection, it will be noted that the liquid in the y.recess portion 226 is permitted to pass through the openings 231 `in the washer 228 into .the recess portion.227 sc that the yclosing of thevalve is'not prevented.

Means are provided for automatically permitting the closing ofthe valve 41 to cut off further flow of liquid throughthe.rneterwhenevergasI enters the line and accumulates in the fair eliminator in *such quantity .as "to cause openingof'the `valves thereof. Thus, gas isxprevented from passing through the meter and causing a false indication of the volume of liquid passing through the meter.

As `stated above, `the cut-off valve 41 is so constructed that the valve is normally urged toward closed position. However, Iwe provide valve control mechanism 249 for holdingthe valve in open position during normal operation of the system. Such mechanism is arranged to oper-ate to permit the valve to close whenever gas enters the system. In FIG. 16 the mechanism is shown in the position corresponding to the open position of the valve.

To .the foregoing end a latch rod 250 is pivotally connected to the crank 223 and is slidably guided in -a portion 251 of the framef-and is formed adjacent the other end withla latchingnotch 252. A dog 253 is pivotally mounted 4on the frame .in .positionto `engagethe notch 1 1 252 and Vis suitably urged in a counterclockwise direction as by a spring 254 bearing against a fixed clip 255 to maintain engagement With the latch 252 and hold the rod 250 and connected crank 223 in such ya position (as shown in FIG. 14 for example) that the valve 214 is maintained in its open position.

A latch tripping means is mounted adjacent the latch 253 and includes `a closed cylinder 256 in which is slidably disposed a piston 257 which carries `a latch tripping rod 258 projecting through an opening 260 in the cylinder end wall, which opening vents the corresponding side of the cylinder to atmosphere. The rod 258 is pivotally connected to a link 271, which in turn is pivotally connected to one arm of a Y cam 272 pivotally connected at its center to the free end of the latch dog 253 and hav-ing its free camming arms bearing against a fixed clip 262. The cam 272 is arranged to rotate the latch 253 in a clockwise (unlatching) direction when the piston 257 is moved in an appropriate direction (to the right as viewed in FIG. 16). The cylinder 256 on the right hand side of the piston 257 is Vented through the opening 260. The arrangement is such that the latch dog 253 normally is urged into latching position by the spring 254 and the piston 257 is positioned midway of its stroke in the cylinder 256. The latch dog 253 is moved out of its latching position, or tripped when pressure is applied to the cylinder through the pipe 143 which is connected to the pressure side of the cylinder.

In lieu of the piston 257 a flexible diaphragm (not shown) suitably secured in the casing 286 may be employed to perform the function of the piston.

The crank 223 is provided with a reset arm 261 by which it may be reset manually after the latch has been tripped.

Under normal conditions of operation only liquid passes through the line and there is no gas passing therethrough. Accordingly the latch after having been moved to latching position, remains in such position and the cut-olf valve is held in open position to permit liquid to pass therethrough.

When there is no gas passing through the line, the float 172 of the air `eliminator remains in its upper position and the air eliminator valves 151a and 151b remain closed. The pressure on the fluid in the air eliminator chamber 131 is equal to the sum of pressure in the tank 24 plus the pressure resulting from the static head of the liquid less the pressure losses in the line. The pressure in the air eliminator chamber 147b and the pipe 144 is at least equal to atmospheric pressure and may be as great `as the pressure in the tank 24. The gas in the chamber 147a, the pipe 143 and the cylinder 256 is at atmospheric pressure. However, the reed valve 163 prevents any back flow of gas from the chamber 147a to the chamber 147b.

.- Should Aany gas enter the line, it rises in the float chamlber 131 of the air eliminator 39 and consequently dos not pass through the meter 40. The gas which collects above the liquid in the float chamber is, of course, at the same pressure as that of the liquid in the line.

As gas collects in the float chamber 1311, the lloat 172 descends accordingly until it reaches a point -at which it causes the valves 151a and 151b to open. Upon the opening of the valves 151a and 151b the pressure that has been built up on the gas in the float chamber is suddenly transmitted to the cylinder at the pressure side of the piston 257. This sudden pressure is suicient to move the piston 257 to trip the latch 253 and permit the valve 41 to close, thereby preventing further ow of liquid or gas through the line.

It should be noted at this point that the apparatus is so designed that the air eliminator valves open to iactuate the tripping mechanism and permit the cut-off valve to -close before any gas passes through the meter.

Gas passes out of the air eliminator through the pipe 144 and'is discharged into the tank 24. When liquid ow is again established in the line, the oat 172 again rises to close the valves151a and 151b. The check valve 144e prevents any reverse llow of gas from the tank 24 to the air eliminator 39. The valve 41 is then opened and the latch 253 reset to hold the valve 41 open, which operation is performed by manually rotating the crank in a clockwise direction. The pressure created in the cylinder 256, the pipe 143 and the chamber 147e by the resetting of the latch 253 is relieved through the passage 148, and the reed valve to the chamber 147b.

It will be understood that when liquid ow is reestablished in the line, the gas which is trapped in the manifold and the line gravitates upwardly out of the pipe 144. The handle 223 will not latch open until such gas `is eliminated from the manifold and line and the air eliminator valves are closed.

It will be seen that the arrangement is such that there is no possibility Iof losing the pressure on the tank 24 by reason of the complete emptying of a compartment of the tank. Whenever all of the liquid passes from the compartment and gas enters the line, this causes the air elimina- -tor 39 to open and cause the cut-ott valve 41 to close. Gas discharged from the air eliminator to the cylinder 2,56 is trapped therein. Gas discharged from the air eliminator through the pipe 144 is returned to the tank 24, and back flow from the latter is prevented by the check valve 144g.

In the operation of the apparatus in accordance with my invention, the `apparatus is connected in the liquid line (not shown) and ia valve or other control means (not shown) actuated to permit the liquid to be measured to llow through the apparatus.

As the liquid flows through the strainer 38 any solid impurities are removed by the strainer and the liquid passes therefrom free of such solid particles. l

The liquid then ows through the meter 40 and causes the rotors to be rotated which, as above explained, effect rotation of the counter and thereby provides an indication of the quantity of liquid which flows through the meter. So long as only liquid and no gas flows through the line the shut-olf valve 41 remains open and the liquid may llow freely. On the other hand, should any gas enter the line, it will, as above explained, enter the float chamber of the air eliminator 39 and when sufficient gas has collected therein, the air eliminator valves will open to actuate the tn'p mechanism 249 to allow the shut-o valve 41 to close and thereby prevent any likelihood of the gas passing through the meter and causing a false indication on the counter. When this occurs and after the air has been exhausted from the air eliminator and the latter is closed, the operator resets the shut-off valve in open position, whereupon the -flow of the liquid continues.

Application of my invention to a tank discharging system in which the discharge of the liquid is aided or effected by a pressure pump is illustrated in `FIG. 17 of the drawings to which reference now is made.

In the system illustrated, -a tank 300 is provided which is divided into a plurality of compartments 301, each of which is vented to atmosphere to a suitable vent pipe 302. The several compartments 301 respectively are connected by outlet pipe 303 to manifold valves 304 which in turn are connected to a single outlet pipe 305 which leads to a pump 306 of any known construction suitable for forcing liquid through the discharge line as hereinafter explained.

The outlet pipe 305 connected to an assembly'307 which `for the purpose of illustration is similar to the corresponding assembly illustrated particularly in IFIGS. 1, 3 and 4 of the drawings and described in connection with the rst embodiment of the invention. The assembly 307 includes a strainer 308, an air eliminator 309, a meter 310, a cut-off valve 311 and a valve control mechanism 312, all of which elements are constructed and function in a manner similar to the corresponding elements of the assembly in FIG. l, except as hereinafter pointed out.

1s The outlet of the cut-off valve 311 `connected to a discharge line 313 to which is attached a faucet`314. One side of `the air eliminator 309 is connected by a pipe 315 to the cylinder of thevalve control mechanism 312 in a manner similar to `that shown'in FIG. 16. Leading from the other side of the air eliminatoriis a vent pipe 316 which terminates in one ofthe compartments 301 `above the level of the liquid therein for vapurpose which Will hereinafter appear. A check valve 317 is provided in the vent pipe`31'5, so arranged asto prevent the iiow of air therethrough in aidirection from the tank toward the -air eliminator.

V`When the t-ank300 is to` be discharged, the appropriate valve 304 is opened and the pump A306 energized to` withdraw'liquid from the compartment and pump it Vthrough the strainer, meter, cut-oli' valve and discharge line, when the faucet A314 is opened. AShould any air or other gas enter the-line ahead of the air eliminator, it will rise in the air eliminator-chamber in a manner similar to that hereinabove described, and when suicient air or gas has accumulated in the chamber the air eliminator valves open and gas passes through the pipe 315 to actuate the valve `control mechanism andftrip the same to allow the cut-off valve to Aclose, thus halting further How of -liquid through the line. Air is discharged from the air eliminator through the vent pipe 316 into the compartment301 until the operator closes the empty compartment manifold valve and opens the manifold valve of a compartment i containing liquid.

The arrangementshown in FIG. 17 is capable of discharging liquid to a tank or container below, or above or at the same level as the tank 300.

A system wherein the tank is discharged solely vby gravity is illustrated in FIG. 18 of the drawings to which reference now is made. The tank 400 is provided with compartments 401 which are vented in a manner similar to the compartments 301 hereinabove described and are connected through pipes 403 to manifold -valves 404. r[lhe manifold valves are connectedby an outlet pipe 405 to an assembly 407 which is similar to the assembly 307 except as hereinafter explained `and the cut-olf valve 411 thereof is connected to a discharge line 413 leading to a tank 414 into which the liquid is to be discharged and which is located at a level sufficiently below the tatnk -400 to `allow liquid to be discharged by gravity. The vair eliminator 409 is connected atone lside through a pipe 415 tothe valve -control device 412 and at the other side through a pipe 416 to the discharge side of the cut-off valve 411.

In the operation of the system shown in FIG. 18 the tank is discharged by opening the selected manifold Valve 404, whereupon the liquid flows by -gravity from the corresponding compartment 401 through the corresponding outlet pipe 403 and the outlet pipe 405 `and through the assembly 407 and line 413 to the tank 414. Whenever air or other gas is present in the line and collects in su'icient quantities in 'the chamber of the air eliminator 409, the air eliminator valves are opened and the piston of the mechanism 412 is exposed-to less'than atmospheric pressure and thereupon operates to close the cut-olf valve `411 and halt further ow of liquid to the line. The opening of the air eliminator `establishes a connection from the pipe 405 to the line 413 by-passing thevalve `411 (as well as the meter 412) which serves to break the vacuum in the discharge line 413, so that the liquid in the line beyond the cut-off valve 41'1 continues to iiow at least until the air in the system has been withdrawn such an extent that the air eliminator valves again close.

Referring now to FIG. 19 there is illustrated `a system wherein the liquid is withdrawn from the tank by the action of a `pump which creates suction on the liquid within the tank, which pump serves to aid the action of gravity in discharging the tank or serves as the sole means for withdrawing the liquid from the tank.

The tank 500 is similar to the tank 400 and preferably `is provided with individual Vcompartments 501 each "of whichfis ventedtothe atmosphere and is provided with outlet pipes 503 for Ywithdrawing liquid therefrom which latterpipesare connected to manifold valves 504. The manifold valves are connected totav single outlet pipe y506 which in'turn is connected to an assembly 507 similar to the assembly "407 hereinabove described. The assembly 507 is provided with a discharge line 5'13 for discharging to a tank 514 and a pump 505is connected in the discharge pipe "513 for creating a suction to withdraw'the liquid from the tank 500.

'The system illustrated in FIG. 19 is the same in all respects to the system illustrated `in FIG. 18 and above described `except that the pump 505 is inserted in the discharge line 513 and serves to effect the withdrawal `of the liquid `fromthe-tank so that it may be Withdrawn even though the tank "514 into which the liquid is to be discharged is `above the level of the tank 500 and therefore it is not necessary to rely upon the action of gravity to discharge thetank 500. This system functions `in a manner similar to that of the system shown in FIG. 18.

It will`be understood that while I have shown and described a meter in the liquid line, the meter maybe omitted. There are numerous applications of my invention in its broader aspects wherein it is not desired `to measure the ow, but where it is desirable, for reasons referred to"hereinbefore, to insure that no air or other gases pass through the line. It will be understood that my shut-olf mechanism functions in a manner similar to'that described in a system where no meter is employed. `In such a system the cut-off Valveis connected directly to the casing on which the -air eliminator headris located. In'thisA system, the cut-off mechanism serves to prevent the passage of air or other fluid through the line, with allthe resultant advantages herein explained, except that of preventing an incorrect indication by the meter.

It will"be understood that instead of providing a single air eliminatorhavi'ng la single inlet and a pair of outlets one connected to the tank to discharge air from the line intothe tank and the other connected to the control-cylin der, I may provide in lieu thereof two separate air eliminators (not shown) each of the single outlet type connected in such a manner as to perform the functions of the single air eliminator shown.

`While I`have described the functioning of the apparatus in collecting "and discharging air or otherI `gas and for preventing the passage of the same through the line, it will be understood that it is also well adapted to prevent thepassage of and to dischargea lighter and immiscible liquid.

It will be seen that my invention provides apparatus halting theflow ofliquid through a line whenever` air `or other gas or a second lighter and immiscible liquid enters the line. lThe apparatus automatically operates to collect and discharge the second iiuid from the line and to prevent `it 'from passing beyond the air eliminator.

The cut-olf means is automatically actuated by the presence o'f air or gas in 'the line, and therefore-itidoes not require any attention except that in the embodiment of the `invention shown it mustbe reset after it has `operatedto cut on? the flowof liquid through the line.

The "apparatus, when a ymeter is included therein, pro-V vides means for accurately measuring the amount of liquid passing therethrough. The cut-olf means prevents the passage of air or other uid through the meter so that there is no likelihood of any false indication such as might otherwise result owing to the passage of the air or other gas through the meter.

The apparatus is relatively simple yand therefore may be manufactured and assembled relatively inexpensively. Moreover, the `apparatus is such that it may be installed in any line Without the necessity for reconstructing or substantially modifying the structure of the line. The apparatus is simple and positive in action, and requires 'maaier 15 .A s a minimum of servicing and attention and a minimum of repair or replacement of parts over a. long period of use.

The apparatus is simple, light yand compact, and therefore where installed in `a truck or truck-trailer does not -add greatly to the weight of the truck or truck-trailer combination. Moreover, it requires only 4a relatively small space for installation and therefore does not in any way encumber the truck or truck-trailer combination on which installed or interfere in any way with the normal and usual mode of operating such vehicles. It will be understood that the` apparatus is also well adapted for use in a stationary installation. Also its use is not limited to discharging a portable tank into a iixed tank but may beyemployed in discharging one portable tank into another, or a fixed -tank to a portable tank.

Among the other advantages of the invention is its function of maintaining the pressure on the several compartments of a pressurized tank such as in the embodiment shown in FIGS. l to 15. Thus should the operator fail to close the manifold valve of a compartment when all of the liquid has been withdrawn therefrom, the apparatus will operate to close the line and prevent the passage of gas through the discharge line.

`Other advantages of the invention are that it imposes no additional pressure loss in the line; it operates equally well Iwith gravity, pump suction, pressurizing or pump discharge of the tank; it does not increase the net weight or size of the meter cut-olf mechanism combination; is uid tight; requires no linkage immersed in the product which may become corroded, gummed or inoperative; is not adversely `atiected by turbulent llow; provides a positive action -to close the line when air or other gas enters the line; is free of wire drawing, vaporization and consequent inaccuracy; interposes no obstruction to the normal function of the preset valve; is not dependent upon the ,specific gravity of the product; and serves to relieve the sun pressure or increase in pressure due to rise in ,temperature of the uid within the line.

This application is a continuation of my copending application Serial No. 553,506, filed December 16, 1955, now abandoned.

I claim:

l. Apparatus for controlling the flow. of a primary fluid in liquid lform through a conduit comprising la cutolf valve in the conduit, means constantly urging said valve toward closed position, means yfor releasably holding said valve in openrposition, collection and discharge means for collecting a second iluid immiscible with and lighter than said primary il'uid, said collection and discharge means including a chamber connected to said conduit ahead of said valve and having an outlet, a discharge valve controlling the discharge of said second uid from said chamber through said valve, a oat in said chamber, means connecting said oat land said discharge valve whereby to discharge said second fluid upon the collection of a predetermined quantity thereof in said chamber and means actuated by the pressure of said second fluid discharged from said collection and discharge means for releasing said lholding means.

2. vApparatus for controlling the ilow of liquid through a conduit comprising -a cut-off valve `connected in said conduit for closing said conduit, and normally urged toward closed position, means releasably holding said valve in open position, means actuated by the pressure of gas discharged from the conduit ahead of said valve for releasing said holding means, and means for discharging gas from the conduit ahead of said cut-oi valve to thereby actuate said releasing means, said last means including a float chamber having an inlet connected to said conduit ahead of said valve and an outlet connected to said releasing means, a control valve controlling said outlet, a iloat in said chamber, and means connecting said iioat and said control valve for closing'said control valve when the liquid in said chamber rises. above a prede- 16 termined level and for opening said control valve when said liquid falls below said level. Y

3. Apparatus for controlling the flow of liquid through a conduit comprising a cut-off valve connected in said conduit Ifor closing said conduit, and normally urged toward closed position, means releasably holding said valve in open position, means actuated by `the pressure of gas discharged from said conduit `ahead of said valve for releasing said holding means, and means for discharging gas from the conduit to thereby actuate said releasing means, said last means including a housing defining a oat chamber connected to the conduit ahead of said valve, a pair of outlets leading from said float chamber, one connected to said releasing means and 4the other discharging to 'atmosphere beyond said cut-olf valve, a control valve controlling each of said outlets, ya float in said chamber, and means connecting said float to said control valves for closing said valves when the liquid in said chamber rises above a predetermined level and for opening said valves when said liquid falls below said level.

4. Apparatus 4for controlling the ow of a primary fluid in liquid form through a conduit comprising a cutoi valve connected -in said conduit -for closing said conduit, and normally urged toward closed position, means releasably holding said valve in open position, means `actuated by the pressure of a secondary fluid immiscible with and of a different specific gravity than the primary fluid discharged from the conduit ahead of said valve for releasing said holding means, and means for discharging said secondary iluid from the conduit to thereby actuate said releasing means, said last means including a float chamber having an inlet connected to said conduit ahead of said valve and an outlet connected to said releasing means, `a control valve controlling said outlet, -a float'in said chamber, and means connecting said tdoat and said control valve for actuating said control valve when the primary nid in said chamber reaches a predetermined level in said chamber.

5. Apparatus `for controlling the flow of a primary fluid in liquid form through a conduit comprising a cutol valve connected in said conduit for closing said conduit and normally urged toward closed position, means including a latch releasably holding said valve in open position, means actuated by the pressure of a secondary fluid immiscible with and of a diierent specific gravity than the primary iluid discharged from said conduit ahead of said valve for tripping said latch, and means for discharging said secondary fluid from the conduit to thereby actuate said latch-tripping means, said last means including ya housing defining a iloat chamber connected to Ithe conduit ahead of said valve, a pair of outlets leading from said float chamber, one connected to said releasing means and the other discharging to atmosphere beyond said valve, a control valve associated with each of said outlets, a float in said chamber, and means connecting said float to said control valves for actuating said control valves when the primary duid in said chamber reaches a predetermined level.

6. In a liquid transmission system having means for creating a pressure differential therein for inducing transmission of a primary liquid, means for accumulating foreign fluid immiscible with and having a different speciiic gravity than said primary liquid and for interrupting liquid transmission in the event of accumulation within said system of -a predetermined quantity of foreign uid; said means including av chamber connected to said system at a point subjected to substantial line pressure differential for collecting foreign uid by virtue of diierence in specific gravity between said primary liquid and said foreign duid, valve means downstream of said chamber for controlling said liquid transmission, said valve means including a valve, spring means urging said valve closed, latch means releasably holding said valve open, and fluid pressure actuated means for releasing said latch means, a passage for conveying foreign iluid under pressure to said', releasingqmeans,` a controLvalve-openable to permit the dow of foreign uid from'saidr chamber to said passage, 1a oat within said chamber of such effective specic graVty-astO-Seek the-plane of demarcation between said primary liquid andsaidforeign uid, means connecting said oat to'saidl control-valve whereby said float opens said control valve when said foreign fluid accumulates beyondapredetermined' quantity in` said chamber, and closes saidvalvewhen said foreignfluid decreases below a predetermined quantity, and bleeder means for permitting restricted ow of duid from said passage to exhaust means.

7. In a liquid transmission system having means for creating a pressure differential therein for inducing transmission of a primary liquid, means for accumulating and exhausting from said system foreign fluid immiscible with and having :a different specific gravity than said primary liquid and for interrupting liquid transmission in the event of accumulation Within said system of a predetermined quantity of foreign fluid; said means including a chamber connected to said system at a point subjected to substantial line pressure dilerential for collecting foreign uid by virtue of difference in specic gravity between said foreign nid and said primary iiuid, a control valve openable to permit restricted flow offoreign uid from said chamber to exhaust means, valve means downstream of said chamber for controlling said liquid transmission, said valve means being closable by actuation by duid pressure, a passage for conveying foreign fluid to said valve means, a second control valve openable to permit the flow of foreign fluid from said chamber to said passage, a oat within said chamber of such effective specific gravity as to seek the plane of demarcation between said primary liquid and said foreign uid, means connecting said float to both of said control valves whereby said float opens said control valves when said lforeign fluid accumulates beyond a predetermined quantity in said chamber, rand closes said Valves when said foreign uid decreases below a predetermined quantity, and bleeder means 'for permitting restricted flow of uid from said passage to exhaust means.

8. In combination, a tank for containing a primary fluid in liquid form, a discharge line leading from said tank, a cut-off valve in said discharge line for closing said line, means operative independently of the fluid pressure in said discharge line for closing said cut-off valve, discharge means in said line ahead of said cut-oft valve and including a chamber connected to said line for accumulating a secondary fluid immiscible with and of different speciiic gravity than said primary iuid, val-ve means for controlling the discharge of secondary fluid from said chamber and float means kfor Iactuating said valve means when the primary liquid reaches a predetermined level in said chamber, and means actuated by the pressure of secondary fluid discharged from said chamber for actuating said valve closing means.

9. In combination, a tank for containing a primary iluid in liquid form, means for applying a gaseous pressure on the liquid in said tank, a discharge line leading from said tank, a cut-off valve in said discharge line for closing said line, means operative independently of the pressure in said discharge line for closing said cut-olf valve, discharge means in said line ahead of said cut-off valve and including a chamber connected to said line for accumulating a secondary fluid immiscible with and of different specic gravity than said primary fluid and valve means for controlling the discharge of secondary iiuid from said chamber, and oat means fo-r actuating said valve means when the prim-ary liquid reaches a predetermined level in said chamber, means lfor returning .to said tank secondary uid discharged from said chamber and means actuated by the pressure of secondary iluid discharged from said chamber for actuating said valve closing means.

10. In combination, a tank for containing a primary fluid in` liquid form, a discharge line leading from said tank, a cut-,otfvalve insaid discharge line for closing said line, means operative independently of the pressure in said` discharge line for closing said cut-01T valve, discharge means in said line ahead ofV said cut-off valve and including a chamber connected to said line for accumulating a secondary fluid immiscible with and of different speciic gravity than said primary uid, control valve means for controlling the discharge of secondary uid from said chamber, and float means for actuating said control valve means when the primary fluid reaches a predetermined level in said chamber, means for discharging secondary uid from said chamber into said line on the downstream side of said cut-off valve, and means actuated by the pressure of secondary uid discharged from said chamber for actuating said valve closing means.

1l. In combination, a tank for containing a primary iluid in liquid form, a discharge line leading from said tank, a cut-olf valve in said discharge line for closing said line, means operative independently of the pressure in said discharge line for closing said cut-oif valve, discharge means in said line ahead of said cut-olf valve and including a chamber connected to said line for accumulating a secondary fluid immiscible with and of different specific gravity than said primary fluid, valve means for controlling the discharge of secondary fluid from said chamber, and oat means for actuating said valve means when the primary liquid reaches a predetermined level in said chamber, a suction pump in said line on the downstream side of said discharge means, means for discharging secondary iluid from said chamber into said line on the downstream side of said cut-olf valve and ahead of said pump, and means actuated by the pressure of secondary uid discharged from said chamber for actuating said valve closing means.

12. Apparatus for controlling the flow of a primary uid in liquid form through a conduit comprising a cutoif valve in said conduit for closing said conduit, means operative independently of the pressure in said discharge line for closing said cut-off valve, discharge means for collecting and discharging from said conduit a secondary uid immiscible with and of a different specific gravity than said primary Huid, said discharge means having a chamber connected to said conduit and a plurality of discharge outlets leading from said chamber for discharging said secondary fluid, discharge valves controlling said outlets, and float means controlling said discharge valves in accordance with the level of the primary iluid in said chamber, means connecting one of said outlets to a point of exhaust for said secondary fluid, and means connecting another of said outlets to said cut-olfI valve closing means for actuating the latter upon the collection of a predetermined quantity of secondary fluid in said chamber and discharge of secondary fluid from said chamber.

13. The invention as set forth in claim l2 wherein a bleeder bypass around said chamber is provided for connecting said outlets and a check valve is provided in said bypass whereby to bleed fluid from said second connecting means to said first connecting means.

14. Apparatus for controlling the flow of a primary fluid in liquid form through a conduit comprising a cutolf valve in said conduit for closing said conduit, means operative independently of the pressure in said discharge line normally urging said valve toward closed position, means releasably holding said valve in open position, fluid pressure actuated means for releasing said holding means, discharge means for collecting and `discharging from said conduit a secondary fluid immiscible with and of a different specific gravity than said primary fluid, said discharge means having a chamber connected to said conduit and a plurality of discharge outlets leading from said chamber for discharging said secondary uid, discharge valves controlling said outlets and a float controlling said discharge valves in accordance with the level of the primary fluid in said chamber, means connecting one of said outlets to a point of' exhaust for said secondary lluid, and means connecting another of said outlets t0 said releasing means for actuating the latter upon the 5 collection of a predetermined quantity of secondary fluid in said chamber and discharge of secondary uid from said chamber.

References Cited in the le of this patent UNITED STATES PATENTS Mitchell Iuly 29, 1924 Justus May 4, 1937 Hazard Jan. 9, 1940 Morgan Aug. 4, 1942 Moore et al Jan. 5, 1943 Hundley Nov. 2, 1954 

